Redstart is a lightweight Lisp interpreter written in C++ with a focus on shell scripting. It lets you combine the expressive power of Lisp with the practicality of the Unix shell: you can run commands, capture output, pipe between processes, and still use Lisp syntax for logic and structure. Think of it as writing your shell scripts in Lisp instead of Bash.
Show HN: A Lisp Interpreter for Shell Scripting
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Re: Show HN: A Lisp Interpreter for Shell Scripting
#2awesome! I have wanted something like this for a long time. Currently I use a janet fork https://github.com/eshrh/matsurika> with some trivial additions, the most important of which is a `$` macro that does what the `sh` does here. I have two questions:
- I see that `sh` does not take in strings but instead lisp forms. How do you distinguish between variables that need to be substituted and commands? In my fork, the way to do variable substitution involves quasiquoting/unquoting. - Almost all of the features that make your language good for shell scripting are essentially syntactic features that can easily be implemented as a macro library for say, scheme. Why'd you choose to write in C++? Surely performance is not an important factor here. (I'm interested because I am currently working on a scheme-based shell scripting language).
Re: Show HN: A Lisp Interpreter for Shell Scripting
#3This looks good! I've seen other tries of shell scripting with lisp dialects but Redstart syntax looks more intuitive (from a shell scripting standpoint) and easy to read.
Re: Show HN: A Lisp Interpreter for Shell Scripting
#4Very nice! I've often wondered how close you could get to a POSIX-like syntax with something like this while maintaining a LISP semantics as much as possible. Especially pipelines are much easier to read with the | and > operators.
I guess you need some sort of LISP dialect that supports infix operators
Re: Show HN: A Lisp Interpreter for Shell Scripting
#5If you don't mind .NET, BraidLang is another interesting project.
Re: Show HN: A Lisp Interpreter for Shell Scripting
#6Very nice! I've often wondered how close you could get to a POSIX-like syntax with something like this while maintaining a LISP semantics as much as possible. Especially pipelines are much easier to read with the | and > operators. I guess you need some sort of LISP dialect that supports infix operators
Would take threading macros over pipelines every other day of the week.
Re: Show HN: A Lisp Interpreter for Shell Scripting
#7Related: Schemesh — A Unix shell and Lisp REPL, fused together
https://github.com/cosmos72/schemesh
https://news.ycombinator.com/item?id=43061183 (7 months ago, 177 upvotes)
Re: Show HN: A Lisp Interpreter for Shell Scripting
#8Very nice! I've often wondered how close you could get to a POSIX-like syntax with something like this while maintaining a LISP semantics as much as possible. Especially pipelines are much easier to read with the | and > operators. I guess you need some sort of LISP dialect that supports infix operators
You can have regular shell infix pipes combined with Lisp/Scheme macros as control flow. I think the tradeoff that Schemesh is nice, even though it does sacrifice POSIX:
The best of both worlds of shell and Lisp is quick ability to run and pipe processes, and full programming functionality without the shell scripting shenanigans like obscure semantics and lack of good data structures.
Re: Show HN: A Lisp Interpreter for Shell Scripting
#9For a blend between Lisp and a more traditional POSIX shell, I enjoy Emacs' [eshell](https://www.masteringemacs.org/article/complete-guide-master...).
Re: Show HN: A Lisp Interpreter for Shell Scripting
#10> writing your shell scripts in Lisp instead of Bash.
in a Lisp ;)
Related, for Common Lisp:
- unix in lisp https://github.com/PuellaeMagicae/unix-in-lispMount Unix system into Common Lisp image.
- kiln https://github.com/ruricolist/kiln - an infrastructure (managing a hidden multicall binary) to make Lisp scripting efficient and ergonomic.
- CIEL https://github.com/ciel-lang/CIEL/ - CIEL Is an Extended Lisp is a collection of dozens of libraries useful for mundane tasks (HTTP, JSON, regexps…). It also comes as a binary that is able to run scripts from sources. Scripts that use the built-in libraries start fast without a compilation step. [project of mine]
- discussed here: https://news.ycombinator.com/item?id=41401415
- Lish https://github.com/nibbula/lish - maybe someday a Lisp shell
- SHCL https://github.com/bradleyjensen/shcl - a POSIX shell in CL (stalling)
- lserver https://notabug.org/quasus/lserver/ - live-coding remote function calls for the shell. Write a command in the REPL, and run it instantly in the shell.
I use CIEL ;)
And, built-in: use the --load flag or build a self-contained binary, compiled to machine code with SBCL. It can contain your web assets (html, js etc). A compressed binary weights ±30MB and starts fast. A stripped off binary with LispWork$ (no compiler, no debugger etc) is ±5MB. There's ECL too.